Keele Research Repository

A weakly nonlinear analysis is conducted for localized necking of a hyperelastic solid cylinder under axial stretching based on the exact theory of nonlinear elasticity. The amplitude equation derived is shown to be consistent with the one-dimensional model recently proposed by Audoly and Hutchinson (J. Mech. Phys. Solids 97, 2016, 68–91). It is shown that results based on the infinite-length approximation are sufficiently accurate even for cylinders with very moderate length/diameter ratios. In contrast, a weakly nonlinear analysis based on the finite length is only valid for very stubby cylinders and for axial force much closer to its bifurcation value than anticipated.